It has long been known to manufacture face-laminated wood stock on a continuous basis from wood strips of random length by assembling the strips in face-to-face relationship with heat curable glue between the adjacent faces of the strips and feeding the assembled strips between the confronting, inner, parallel runs of a pair of continuously moving chains or belts. The inner runs of the chains or belts apply pressure to the opposite faces of the assembled stock while continuously advancing the stock. Curing of the adhesive is accelerated by passing the stock between upper and lower radio frequency (RF) electrodes while the stock is within the confines of the continuous press. Parameters including the capacity of the RF generator and the speed of the stock are adjusted so that the adhesive is completely cured when the stock emerges from the continuous press.
One problem with prior art continuous presses of the kind described above is that arcing or RF energy leakage can occur between the electrode connected to the RF source and surrounding metallic structure, such as frame members, drive chains, and so forth. Such arcing or leakage results in RF energy losses and consequent failure to adequately cure the glue along the glue lines.
Another problem with some prior art continuous presses is that they do not apply sufficient pressure to the laminated wood product uniformly along the entire length of the RF curing stage. As a result, localized separations can occur between adjacent strips. Such separations can allow arcing between the RF electrodes and burning of the adhesive resulting in gaps along the cured glue lines of the finished product.